Mutations in the RpoB Gene of Multidrug-Resistant Mycobacterium Tuberculosis Isolates from Semarang, Indonesia

ABSTRACTTuberculosis is an infectious disease which occurs widely in the world and becomes one of the top 10 causes of death worldwide. Mutations of the RpoB gene cause the resistance of Mycobacterium tuberculosis to rifampicin that contributes to the occurrence of MDR-TB. This study aimed to determine the pattern of rpoB gene polymorphisms in the MDR M. tuberculosis in Semarang, Indonesia. Most mutations occurred at codon Ser531Leu (13 isolates), codon Gln490Lys (7 isolates) and codon 526 (5 isolates). Variations of mutation mostly occurred at codon 526 with 4 variations of nucleotide changes, including His490Leu, His490Cys, His490Ser and His490Tyr. The types of mutation were missense mutations (30 mutations) and silent mutation (1 mutation). The mutations in the rpoB gene of MDR M. tuberculosis isolates in Semarang showed genetic variations that caused high levels of resistance to rifampicin. Keywords: MDR M. Tuberculosis; rpoB gene mutations; rifampicin resistance